Brush-holder



Feb. 12, 1935. Q

R. w. OWENS BRUSH HOLDER Filed July 1, 1932 INVENTOR A ZPynW/YQQ/ 0/ /75,

ATTbRNEY Patented Feb. 12, 1935 UNITED STATES PATENT OFFICE BRUSH-HOLDER of Pennsylvania Application July 1, 1932, Serial No. 620,334

8 Claims.

. 15 the brush-holders may be either mounted or dismantled without removing the end-bell from the main frame of the dynamo-electric machine.

Another object of my invention is to provide for supporting one or more brush-holders on a single through-bolt that is carried by the end-bell of a dynamo-electric machine, and thereby facilitate the mounting and dismantling of the brushholders.

Other objects and a fuller understanding of my 25 invention may be had by referring to the following description, taken in conjunction with the accompanying drawing, in which:

Figure 1 is a side elevational view of a dynamoelectric machine embodying the features of my 30 invention, the top cover plate being removed to illustrate the general features of my invention.

Fig. 2 is an enlarged fragmentary cross-sectional view taken along the line II--II of Fig. 1, and

Fig. 3 is a fragmentary cross-sectional view, partially in elevation, of my brush-rigging attachment taken along the line III-III of Fig. 2.

With particular reference to Fig. 1, the reference character 10 designates a dynamo-electric machine having collecting rings 12 and an apertured end-bell 11 to which my brush-rigging attachment may be readily applied. In general, my brush-rigging attachment comprises a throughbolt 15 having a nut 16, a plurality of stepped insulating blocks 14, a plurality of brush-holders 13 having oppositely extending arms which embrace a portion of the collecting rings 12, and a set of brushes 25 slidably carried by the extending arms of the brush-holders 13.

As best illustrated in Fig. 3, the insulating blocks 14 and the top engaging portion 1'7 of each of the brush-holders 13 are stepped so that, when they are mounted upon the through-bolt 15, they provide a composite interlocking engagement 55 with each other. For securely holding the ex- (Cl. TIL-324) tending arms of the brush-holders 13 in a fixed position relatively to the collecting rings 12, the end-bell 11 is provided with a shoulder 22 which engages the top surface of the stepped-portion of the right-hand insulating block. The internal diamter of the opening in the stepped-insulating blocks 14 is somewhat less than the internal dimeter of the opening in the top engaging portion 17 of the brush-holders 13. Therefore, the brushholders, when mounted upon the through-bolt 15,

are insulated from each other, as well as from the frame of the dynamo-electric machine. Also, the outer surface of the stepped-insulating blocks 14 extends outwardly beyond the top engaging portion 17 of the brush-holders 13 so as to constitute an insulating barrier or rib between the adjacent brush-holders 13. In this manner, dust and other foreign particles are not so apt to decrease the dielectric strength between adjacent brush-holders.

The brush-holders 13 and the stepped-insulating blocks 14 are structurally the same and are readily renewable. In accordance with the usual practice of constructing brush-holders, they may be suitably made either of metal stampings or of a; casting them in one solid piece. In actual practice, I preferably employ brush-holders that are cast of one single piece. At a point substantialhr midway of the extending arm of the brushholders 13, and embracing substantially 45 U mechanical degrees, I provide a suitable apertured portion 23 for holding the brushes 25. The apertured portion 23 is such that the brushes 25 may freely slide within the apertured portion.

As best illustrated in Fig. 2, the brushes 25 a are yieldingly constrained to slidably engage the collecting rings 12 by means of convolute springs 29. The inner end of the convolute springs 29 is carried by a slotted stud 30 and the outer end of the convolute springs 29 is so shaped as to yieldingly engage the top of each of the brushes 25. The slotted stud 30 is provided with two diametrical slots so that the brush pressure may be suitably varied to accommodate the operating conditions of the dynamo-electric machine. For 4:- instance, should it be desirable to increase the brush pressure, it is only necessary to slide the inner end of the convolute springs 29 out of the horizontal slot of the slotted stud 30, being the position shown in Fig. 2, twist the inner end of the springs in a direction to increase the brush pressure, and insert the inner end of the springs in the vertical slot. As is apparent, the brush pressure may be further increased by advancing the inner end of the convolute springs 29 another dynamo-electric machine.

one-quarter turn. In this manner, the brush pressure may be suitably adjusted at'a proper operating value by merely inserting the inner end of the convolute springs 29 in the proper diametrical slot of the slotted stud 30. As illus trated, the shunts 31 of the brushes 25 may be electrically connected to each of the extending arms of the brush-holders 13 by a screw 35 or other suitable means. Accordingly, the current, upon leaving the brushes 25, flows through the shunt 31, the extending arms of the brush-holder 13 and thence to the conductor leads 3310f the As best illustrated in Figs. 1 and a; the brush-i holders 13 may be readily dismantledbymerely unscrewing the through-bolt 15 until the nut 16 is free; withdrawing the through-bolt, and then removing the brush-holders 13 through the apertured portion of the end-bell 11. the brush-holders, it is only necessary to align the insulating blocks 14, the upper engaging end of the brush-holders 13 and the nut 16; insert the through-bolt 15, and then turn the bolt until the insulating-blocks and the upper engaging por-- tion 17 of the brush-holders are so securely interlocked together as to hold the extending arms of the brush-holders 13 in a fixed position rela V tively to the collecting rings '12. Accordingly, it is unnecessary to remove the end-bell 11 when dismantling and replacing the brush-holders. As shown in Fig, 1, the apertured end-bell 11 may be provided with suitable covers 40 to prevent dust and other foreign matter from entering the dynamo-electric machine.

Since certain changes in my invention may be made without departing from the spirit and scope thereof, it is intended thatall matters contained in the foregoing description and shown in the accompanying drawing shall be interpreted as illustrative and not in .a limiting sense.

I claim as my invention:

1. The combination, with a dynamo-electric machine having a rotatable collecting surface and an apertured end-bell, of a bolt detachably carried by the end-bell, a plurality of blocks having recesses mounted on the bolt, a brushholder designed to engage said recesses supported between theiblocks, a nut threadably engaging the inner end'of the bolt for rigidly securing the brush-holder in a fixed position relativelyto the collecting surface, and a brush carried by the brush-holder forv engaging the collecting surface. f

'2. The combination, with a dynamo-electric machine having a rotatable collecting surface and an apertured end-bell, of a bolt detachably carried bythe end-bell, said bolt extending substantially parallel to the collecting surface, a plurality of blocks having recesses mounted on the bolt, a'brush-holder designed to engage said recesses supported'between the blocks, a nut threadably engagingthe inner end of the bolt for rigidly securing the brush-holder in a fixed position relatively to the collecting surface, and a brush carried by the brush-holder for engaging the collecting surface.

The combination, with a dynamo-electric For mounting the brush-holders in a fixed position relatively to the collecting surface, and a brush carried by each of the brush-holders for engaging the col-' lecting surface.

a. The combination, with a dynamo-electric machine having a rotatable collecting surface and an end-bell having'a relatively large aperture, of a bolt detachably carried by the end-bell, said bolt extending substantially parallel to the collecting surface, a plurality of engageable-insulating blocks mounted on the bolt, a plurality of brush-holders supported by the engageableinsulating blocks, each of said brush-holders having two oppositely extending arms, 'a'nut threadably engaging the innerend of the bolt. l

for rigidly securing the brush-holders in a fixed position relatively to the collecting surface, and a brush carried by'each of the arms of the brushholders for engaging the collecting surface.

5. The combination, with a dynamo-electric machine having a rotatable collecting surface and an-end-bell havinga relatively large'aperture, of a bolt detachably carried by the endbell, said bolt extending substantially parallel to the collecting surface, a plurality of engageable insulating blocks mounted on the bolt, a plurality of brush-holders mounted between, and carried by, the engageable-insulating blocks, each of said brush-holders'having two oppositely extending arms, a nut threadably engaging the inner end of the bolt for compressing the engageab1eeinsulating blocks into rigid cooperative relation with the brush-holders and thereby securing the brush-holders in a'fixed position said blocks being provided with channels on both sides of the blocks, a plurality of brush-holders mounted longitudinally of the support, each of said brush-holders being provided with channels on both sides thereof, said blocks and brushholders being disposed in consecutive alternation on the support the number of blocks being greater by one than the number of brush-holders and the channels on the blocks and brush-holders being constructed to interfit, or mate, with each other, means for maintaining rigid inter-engagement of the blocks and brush-holders upon said support, and a brush for engaging the collecting surface carried by each brush-holder.

V RAYMOND w. OWENS. 

